page 1
page 2
page 3 page 4
page 5
page 6
page 7
page 8
page 9
page 10
page 11
page 12
page 13
page 14
page 15
page 16
page 17
page 18
page 19
page 20
page 21
page 22
page 23
page 24
page 25
< prev - next > Energy Hydro power Layout_and_construction_of_canals (Printable PDF)
A canal is an open-air waterway along which water flows unassisted.
The two main characteristics of every canal are:
- Geometric characteristics and
- Hydraulic characteristics
These are illustrated below.
Geometric characteristics (Fig. 1)
b = inner border
B = Canal bed
B’ = Top base of the canal
b’ = outer border
h = Depth of the canal
ø = Angle of the canal slope
A’ = Cross-cut section of the canal (it can be rectangular,
circular, trapezoidal or triangular)
Hydraulic characteristics (Fig. 2)
Q = Water flow (litres/second)
V = Water velocity (m/second)
A = Area of the cross-section of the mass of water conveyed by the
canal (m2). Its shape will depend on the cross-section of the canal
S = Slope or inclination of the canal bed, expressed in percentage
terms or in so much per thousand
d = Water stress or depth
R = Hydraulic radius. R = A/P
P = Wet perimeter, the sum of two banks and the canal bed
which are in contact with the water
n = Rugosity coefficient. Its value depends on the material the canal
is made of (earth, concrete, stone, etc.).